Field of the Invention
The invention relates to a burner for fuels suitable for spraying, in particular gaseous fuels, having a substantially cylindrical fire tube, a fire tube cover arranged on the upstream end of the fire tube, a fuel nozzle terminating centrally in the fire tube cover and means to feed the combustion air into the fire tube.
Such designs are used above all as standard burners for gas turbines.
Furthermore, the invention relates to a method for burning the fuel suitable for spraying, in particular gaseous fuel, which is fed centrally into a combustion zone where it is mixed with combustion air.
A major objective of modern combustion technology is to produce low-pollutant waste gases. In addition to complete burnout to avoid carbon monoxide, low NO.sub.x values are a particular objective.
Normally, a combustion zone is formed at the burner head, into which combustion zone the combustion air is blown through corresponding openings in the fire tube cover and in the fire tube, thus cooling the fire tube material. Further combustion air is fed in through scale-like openings which are distributed along the entire fire tube.
It has been found that such devices and methods can be improved on. The object of the present invention was therefore to achieve even temperature distribution in the fire tube and thus a reduction in the amount of pollutants produced.
This object is achieved by the device of the aforementioned type in that the means to feed the combustion air into the fire tube exhibit a plurality of first and second air line nozzles, that the first and second air line nozzles are inclined in the direction of counterflow at an angle to the axis of the fire tube, that the first air line nozzles end at the fire tube whilst the second air line nozzles extend into the fire tube and that a first air line nozzle is assigned to each second air line nozzle and arranged upstream directly adjacent thereto.
The method of the aforementioned type to achieve the desired objective is characterised in that the combustion air is blown into the combustion zone in such a manner that a highly turbulent toroidal eddy forms in a plane perpendicular to the direction of flow of the combustion zone, the direction of rotation of said turbulent toroidal eddy inside being against the direction of flow of the combustion zone.